Post by DinosaurMichael on Jan 10, 2012 8:44:37 GMT -5
Spinosaurus - Spinosaurus aegyptiacus
Spinosaurus (meaning "spine lizard") is a genus of theropod dinosaur which lived in what is now North Africa, from the lower Albian to lower Cenomanian stages of the Cretaceous period, about 112 to 97 million years ago. This genus was first known from Egyptian remains discovered in 1912 and described by German paleontologist Ernst Stromer in 1915. The original remains were destroyed in World War II, but additional material has come to light in recent years. It is unclear whether one or two species are represented in the fossils reported in the scientific literature. The best known species is S. aegyptiacus from Egypt, although a potential second species S. maroccanus has been recovered from Morocco. Spinosaurus may be the largest of all known carnivorous dinosaurs, even larger than Tyrannosaurus and Giganotosaurus. Estimates published in 2005 and 2007 suggest that it was 12.6 to 18 metres (41 to 59 ft) in length and 7 to 20.9 tonnes (7.7 to 23.0 short tons) in weight. The skull of Spinosaurus was long and narrow like that of a modern crocodilian. Spinosaurus is thought to have eaten fish; evidence suggests that it lived both on land and in water like a modern crocodilian. The distinctive spines of Spinosaurus, which were long extensions of the vertebrae, grew to at least 1.65 meters (5.4 ft) long and were likely to have had skin connecting them, forming a sail-like structure, although some authors have suggested that the spines were covered in fat and formed a hump. Multiple functions have been put forward for this structure, including thermoregulation and display.
Steppe Rhinoceros - Elasmotherium sibiricum
Elasmotherium ("Thin Plate Beast") is an extinct genus of giant rhinoceros endemic to Eurasia during the Late Pliocene through the Pleistocene, documented from 2.6 mya to as late as 50,000 years ago, possibly later, in the Late Pleistocene, an approximate span of slightly less than 2.6 million years. Three species are recognised. The best known, E. sibiricum was the size of a mammoth and is thought to have borne a large, thick horn on its forehead which was used for defense, attracting mates, driving away competitors, sweeping snow from the grass in winter and digging for water and plant roots. Like all rhinoceroses, elasmotheres were herbivorous. Unlike any others, its high-crowned molars were ever-growing. Its legs were longer than those of other rhinos and were designed for galloping, giving it a horse-like gait. The Russian paleontologists of the 19th century who discovered and named the initial fossils were influenced by ancient legends of a huge unicorn roaming the steppes of Siberia. To date no evidence either contradicts or confirms the possibility that Elasmotherium survived into legendary times. The most reconstructed species is perhaps E. sibiricum by generations of scientists working at the Paleontological Museum in Moscow and elsewhere in Russia. The majority of the fossils fall or have fallen within their national jurisdiction. The dimensions and morphology of the various reconstructions vary considerably. They are for the most part estimating the gross details from the minutiae. However, they all agree on the general order of magnitude, that sibiricum was comparable to a Mammoth and was rather larger than the contemporary Woolly Rhinoceros. E. sibiricum had a measured shoulder height of approximately 2 metres (6.6 ft). To it, however, must be added the height of a massive hump anchored on the fin-like transverse processes extending from the top of the cervical vertebrae, a maximum of 53 centimetres (1.74 ft). The total height then was in excess of 253 centimetres (8.30 ft). The measured length of sibiricum (from a nearly complete skeleton found at Gaevskaya) is 4.5 metres (15 ft). Extrapolation from the greater size of caucasicum molars obtains a length of 5 metres (16 ft)—5.2 metres (17 ft) for caucasicum. According to Legendre's formula, E. sibiricum had a mass of over 4,000 kilograms (3.9 long tons; 4.4 short tons); E. caucasicum, 5,000 kilograms (4.9 long tons; 5.5 short tons). These weights place Elasmotherium in the "really huge" category of all Rhinocerotidae and therefore the animal was "strongly brachyopodial;" that is, they required feet of large contact area to prevent sinking into the soil. The feet were unguligrade, the front larger than the rear: purely tridactyl on Digits II-IV in the rear, but with an extra vestigial digit, I, in the front.
Spinosaurus (meaning "spine lizard") is a genus of theropod dinosaur which lived in what is now North Africa, from the lower Albian to lower Cenomanian stages of the Cretaceous period, about 112 to 97 million years ago. This genus was first known from Egyptian remains discovered in 1912 and described by German paleontologist Ernst Stromer in 1915. The original remains were destroyed in World War II, but additional material has come to light in recent years. It is unclear whether one or two species are represented in the fossils reported in the scientific literature. The best known species is S. aegyptiacus from Egypt, although a potential second species S. maroccanus has been recovered from Morocco. Spinosaurus may be the largest of all known carnivorous dinosaurs, even larger than Tyrannosaurus and Giganotosaurus. Estimates published in 2005 and 2007 suggest that it was 12.6 to 18 metres (41 to 59 ft) in length and 7 to 20.9 tonnes (7.7 to 23.0 short tons) in weight. The skull of Spinosaurus was long and narrow like that of a modern crocodilian. Spinosaurus is thought to have eaten fish; evidence suggests that it lived both on land and in water like a modern crocodilian. The distinctive spines of Spinosaurus, which were long extensions of the vertebrae, grew to at least 1.65 meters (5.4 ft) long and were likely to have had skin connecting them, forming a sail-like structure, although some authors have suggested that the spines were covered in fat and formed a hump. Multiple functions have been put forward for this structure, including thermoregulation and display.
Steppe Rhinoceros - Elasmotherium sibiricum
Elasmotherium ("Thin Plate Beast") is an extinct genus of giant rhinoceros endemic to Eurasia during the Late Pliocene through the Pleistocene, documented from 2.6 mya to as late as 50,000 years ago, possibly later, in the Late Pleistocene, an approximate span of slightly less than 2.6 million years. Three species are recognised. The best known, E. sibiricum was the size of a mammoth and is thought to have borne a large, thick horn on its forehead which was used for defense, attracting mates, driving away competitors, sweeping snow from the grass in winter and digging for water and plant roots. Like all rhinoceroses, elasmotheres were herbivorous. Unlike any others, its high-crowned molars were ever-growing. Its legs were longer than those of other rhinos and were designed for galloping, giving it a horse-like gait. The Russian paleontologists of the 19th century who discovered and named the initial fossils were influenced by ancient legends of a huge unicorn roaming the steppes of Siberia. To date no evidence either contradicts or confirms the possibility that Elasmotherium survived into legendary times. The most reconstructed species is perhaps E. sibiricum by generations of scientists working at the Paleontological Museum in Moscow and elsewhere in Russia. The majority of the fossils fall or have fallen within their national jurisdiction. The dimensions and morphology of the various reconstructions vary considerably. They are for the most part estimating the gross details from the minutiae. However, they all agree on the general order of magnitude, that sibiricum was comparable to a Mammoth and was rather larger than the contemporary Woolly Rhinoceros. E. sibiricum had a measured shoulder height of approximately 2 metres (6.6 ft). To it, however, must be added the height of a massive hump anchored on the fin-like transverse processes extending from the top of the cervical vertebrae, a maximum of 53 centimetres (1.74 ft). The total height then was in excess of 253 centimetres (8.30 ft). The measured length of sibiricum (from a nearly complete skeleton found at Gaevskaya) is 4.5 metres (15 ft). Extrapolation from the greater size of caucasicum molars obtains a length of 5 metres (16 ft)—5.2 metres (17 ft) for caucasicum. According to Legendre's formula, E. sibiricum had a mass of over 4,000 kilograms (3.9 long tons; 4.4 short tons); E. caucasicum, 5,000 kilograms (4.9 long tons; 5.5 short tons). These weights place Elasmotherium in the "really huge" category of all Rhinocerotidae and therefore the animal was "strongly brachyopodial;" that is, they required feet of large contact area to prevent sinking into the soil. The feet were unguligrade, the front larger than the rear: purely tridactyl on Digits II-IV in the rear, but with an extra vestigial digit, I, in the front.
